HealthDay News — Metagenomic next-generation sequencing (NGS) of cerebrospinal fluid (CSF) obtained from patients with meningitis or encephalitis can improve diagnosis of neurologic infections, according to a study published in the June 13 issue of the New England Journal of Medicine.

Michael R. Wilson, M.D., from the University of California in San Francisco, and colleagues conducted a multicenter prospective study to examine the usefulness of metagenomic NGS of CSF for diagnosis of infectious meningitis and encephalitis in 204 pediatric and adult severely ill patients.

The researchers found that among all study patients, the 30-day mortality rate was 11.3 percent. Fifty-eight nervous system infections were diagnosed in 57 patients (27.9 percent); metagenomic NGS identified 22 percent of these 58 infections that were not identified by clinical testing at the source hospital. Metagenomic NGS made the concurrent diagnoses in 19 of the remaining 45 infections. Of 26 infections not identified by metagenomic NGS, 11, seven, and eight, respectively, were diagnosed by serologic testing only, were diagnosed from tissue samples other than CSF, and were negative on metagenomic NGS due to low pathogen titers. Eight of 13 diagnoses made solely by metagenomic NGS had a likely clinical effect, with seven guiding treatment.

“Patients with infectious and noninfectious encephalitis can be clinically indistinguishable from one another,” Wilson said in a statement. “Having a broad-based test that either rules in infection or rules out infection can really aid these cases that are in gray areas between infection and not.”